title: Elastic properties of polyunsaturated phosphatidylethanolamines influence rhodopsin function.
abstract: Membranes with a high content of polyunsaturated phosphatidylethanolamines (PE) facilitate formation of metarhodopsin-II (M(II)), the photointermediate of bovine rhodopsin that activates the G protein transducin. We determined whether M(II)-formation is quantitatively linked to the elastic properties of PEs. Curvature elasticity of monolayers of the polyunsaturated lipids 18 : 0-22 : 6(n - 3)PE, 18 : 0-22 : 5(n)- 6PE and the model lipid 18 : 1(n - 9)-18 : 1,(n- 9)PE were investigated in the inverse hexagonal phase. All three lipids form lipid monolayers with rather low spontaneous radii of curvature of 26-28 angstroms. In membranes, all three PEs generate high negative curvature elastic stress that shifts the equilibrium of MI(I)/M(II) photointermediates of rhodopsin towards M(II) formation.
authors.affiliation: Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, MD 20892, USA.
authors.forename: Walter E
authors.initials: WE
authors.lastname: Teague
authors.forename: Olivier
authors.initials: O
authors.lastname: Soubias
authors.forename: Horia
authors.initials: H
authors.lastname: Petrache
authors.forename: Nola
authors.initials: N
authors.lastname: Fuller
authors.forename: Kirk G
authors.initials: KG
authors.lastname: Hines
authors.forename: R Peter
authors.initials: RP
authors.lastname: Rand
authors.forename: Klaus
authors.initials: K
authors.lastname: Gawrisch
mesh_terms: D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D008027:Light; D008051:Lipid Bilayers / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D012243:Rhodopsin / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D012243:Rhodopsin; C028694:1-palmitoyl-2-oleoylphosphatidylcholine